Pyrometer for internal-combustion engines



April 8 1924.

R. H. LUSCOMBE PYROMETER FOR INTERNAL COMBUSTION ENGINES Filed Nov. 19, 1921 WWI E5555 Patented Apr. 8, 1924.

UNITED STATES PATENT oFF-ICE.

ROBERT H. LUSCOMBE, OF DAVENPORT, IOWA.

rvnomnmnn FOR rnrnmmncomnusrron ENGINES.

Application filed November 1c, 1921. ,Serial No. 516,436.

To all whom it may concern:

Be it known that I, ROBERT H. Lusoomnn,

a citizen of the United States, residing at Davenport, in the county of Scott and State of Iowa, have invented certain new and useful Improvements in Pyrometers for Internal-Combustion Engines, of which the following is a specification.

The present invention consists ofi a pyrometer for internal combustion engines and has for an object the provision of mechanism engageable withthe cylindersof an engine to cause the closing of electric circuits due to the heat generated by the products of combustion in the cylinders,

each circuit being utilized to actuate an in dicator 1n order to visualize the conditlon of each cylinder.

The device ofthis invention is capable of application upon any typeof internal 'combustion engine and the operation thereof is based upon the principle of the thermocouple, or thermoelectric couple. The thermocouples are mounted in the cylinders of the engine so that the hot junctions thereof are exposed to the elements of combustion in the cylinder. The electric current resultant from the heat generated in the cylinder contacting with the hot junction of the thermocouple, is caused to flow through an indicator thereby visualizing the quantity of current in the circuit which quantity is approximately proportionate to the temperature within the cylinder. The temperature average durin the cycle of operation of the engine depen s upon the operative conditions of the cylinder including the com ression and combustion thereof sothat i the compression is weak, a low average temperature is indicated whereas if the compression ing to advantage the manner of connecting one ofthe circuit lead wires thereto.

- YIn thedrawings in order to illustrate the application of this -invention,- aportion of an internal combustion engine 3 is illustr-ated which includes a portion of a cylinder 4 and a portion of-a piston The cylinder is provided witha spark plug openingG and a thermocouple opening 7.

Mounted in the opening 7 of is a thermocouple generally designated 8 which consists of-a cylindrical body provided with externalscrew threads 9 which engage corresponding threads in the cylinders. The inner end of the thermocouplebody is reduced and extended beyond the inner end of the opening 7 so'astoproject into the body of the cylinder 4. The upper end of the'body ofthe thermocouple is enlarged to provide a wrench engaging'portion 10 immediately above the cylinder, fins 11 being formed on'said body above thepor tion10. The fins are, of course, used forthe purpose of cooling. A fiber washer 12 1smounted on the upper end of the thermoco couple body (and has superimposed thereon a head 13 made of brass or other suitable material. An electrode 14 is concentrically mounted in the thermocouple body likewise in the fiber washer 12 and'has its upper end engaged in the lower end of the head 13. Said head is provided with a ,transverse' opening15 through which oneend 16 of a circuit wire cable 17 is mounted. Said end 16 is held from'displacement by a set screw the upper end'of the head 13 and engaged with said end 16. If desired the electrode 14 may be made of copper or constantin or any other suitable metal and thereof. welded to the lower end of the thermocouple body. The hot junction of the thermocou 1e 1s of course at the point where the body is welded to the electrode '14 on the interior of'the cylinder so that the heat 100 from the products of combustion will generate electrical potential and cause the current to flow through the wire of the cable 17. A

circuit wire such as that carried by the cable 17 is engaged with the thermocouple of each 106 cylinder. Each of these wires is engaged.

with a contact. Forinstance, as shown in Fig; 1, the wire 17 is in connection with contact 1, a wire 19 in connection with contact 2, a wire 20 in connection with a contact on p the cylinder 1 en 18 the latter being detachably. mounted in' the lower end 3 and a wire 21 in connection with a contact sists of the three words missf? weak and.

4. This would indicate that there are four cylinders. These contacts are adapted to be engaged by the contact arm of a switch 22. A neutral contact 23 is provided upon which the contact arm of the switch may be normally engaged. The switch 22 is in circuit with an indicator 24 through the medium of circuit wires 25 and 26. The circuit wire 26 is grounded to the engine. The indicator 24 is equipped with an indicating hand which is operable under influence of the electric current passing through the electric wires into the indicatori The face of the indicator bears indicia which is explanatory of the condition of the cylinder with which the thermocouple -is associated. In the present instance the indicator indicia constrong. I

In use of this device it will be apparent that the indicator may be mounted upon the instrument board of a motor vehicle or may be used entirely apart from the vehicle it so,desired. \Vhen the cylinders of the engine are to be tested, the contact arm of the switch may be moved selectively into engagement with the contacts 1, 2, 3 and l to thereby successively determine the condition of each cylinder. .The engagement of the contact arm of the switch with the contacts 1, 2, 3 and 4 will cause the electric circuits to be closed, in an apparent manner, thereby actuating the indicating hand to show the condition of the cylinder.

I have herein described a preferred embodiment of the invention which is illustrative of the principle. It is apparent that various changes may be made in the-mechanical construction within the scope of the claims herewith appended.

\Vhat is claimed is 1. A pyrometer for internal combustion I engines including a thermo-couple adapted to be detachably engaged with an engine cylinder and comprisin two elements one of which-consists of a %ody adapted to be mounted in an opening in the cylinder and to extend into the; combustion chamber thereof, said element having a longitudinal opening extending therethrough, the other element being positioned in said passage and havin one end integrally attached toone end 0 said body, the other end of said element being insulated from the opposite end of the body, said body being grounded to the cylinder and said element being electrically connected to one terminal of a pyrolneter, the other terminal of said pyrometer being grounded. P

2. A pyrometer for internal combustion engines including a thermo-couple adapted to be detachably engaged with an engine cylinder and embodying two elements, one of which is concentrically mounted within the other, said 'elements being welded together at one end and extended into-the combustion chamber of the engine, the opposite ends of said elements being spaced and electrically insulated from each other, a conductive head superimposed on the insulated end of the thermo-couple and engaged with one of the thermo-couple elements, one of the ends of said thermo-couples being grounded to the engine, a conductive member detachably engaged with said head, and a pyrometer one terminal of which is grounded and the other terminal engaged with said conductive member.

In testimony whereof I afiix my signature in presence of two witnesses.

ROBERT H. LUSCOMBE,

'Witnesses W. A. SIEMSEN, IRENE FENNERN. 

